Pipe cutter



July 14, 1942.

B. M. SCIVALLY PIPE CUTTER Filed May 16, 1942 Patented July 14, 1942 UNITED STATES PATENT OFFICE PIPE CUTTER Bernice M. Scivally, Lake Charles, La. Application May 16, 1942, Serial No. 443,267

6 Claims.

This invention relates to a pipe cutter.

An object of the invention is to provide a pipe cutter of the character described adapted to .be lowered into a well to cut off sections of a pipe stuck in the well so that the severed sections may beremoved, as severed, from the well.

In well drilling operations, a drill stem, or other pipe, maybecome stuck in the well so that the entire string cannot be removed and it is then necessary to cut off and remove the pipe a section at a time. The cutter herein described has been designed for that purpose.

Another object of the invention is to provide in a pipe cutter novel means for actuating the cutting bits into cutting relation with the pipe to be severed.

With the above and other objects in view, the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawing, wherein:

Figure 1 shows a side view of the cutter, partly in section, showing the cutting bits in inactive position.

Figure 2 shows a side view, partly in section, showing the cutting bits in active position.

Figure 3 shows a cross-sectional view taken on the line 3--3 of Figure 1, and

Figure 4 shows a cross-sectional view taken on the line 4--4 of Figure 1.

Referring now more particularly to the drawing, wherein like numerals of reference designate similar parts in each of the figures, the numeral l designates a tubular cutter body which is connected to the lower end of a tubular operating string 2 and to the lower end of which a guide 3 is connected. This guide is of conventional construction and is provided for guiding the body over the stuck pipe 4 to be severed.-

The lower end of the cutter body is reduced in internal diameter thus forming an inside annular shoulder 5 and beneath this shoulder the cutter body has a plurality of side slots 6. I'hree of these side slots are shown, although a greater or smaller number may be provided.

Within the cutter body above the shoulder 55, there is an anchor ring 1 which is normally pinned in position in the body by a shearable pin 8. On the anchor ring 1 there is a wear ring 9 and supported On the wear ring 9, within the body, there is another anchor ring H] to which the lower ends of the flexible arms II are secured. The upper ends of these arms converge inwardly and the arms are flexible to pass over the pipe couplings.

Mounted within the slots 6 arethe cutter assemblies. Each assembly comprises a bit carrier 12 whose upper end is pivoted to the anchor ring I and whose lower end carries a laterally directed bit [3; and said assembly also includes a toggle lever l4 whose lower end is pivoted in the corresponding slots 6 and whose upper end is bifurcated and embraces the corresponding carrier I2 and is pivoted thereto by means of a cross pin l5.

The lower end of each slot 6 is concaved forming a seat l6 and the lower end of each toggle lever 14 is correspondingly shaped to work in said seat.

The lower end of each toggle lever l4 also has a vertical slot l1 and a cross pin [8 has its ends anchored to the body and is fitted through said slot. The tool is assembled as shown in Figure 1 with the anchor ring I pinned to the body I by the pin 8, as shown in Figure 1. This will hold the anchor ring I in its upper position with the bit carriers [2 and the toggle levers l4 retracted into, their corresponding slot 6, as shown in Figure 1.

The tool as thus assembled may be lowered into the well and over the stuck pipe 4. The sections of the pipe will usually be connected by enlarged couplings as l9 but as the tool is lowered, the upper ends of the arms II will yield to permit the passage of the tool down over the pipe. A retainer sleeve 20 is located within the body I with its lower end on the anchor ring 10 and with itsupper end opposing the lower end of the operating string 2, as shown in Figures 1 and 2, so that as the tool is lowered, the anchor ring ID will be maintained in its proper position above the anti-friction ring 9. While in this position, the lower ends of the toggle levers M will be spaced above the corresponding seats It as shown in Figure 1.

The outer side of each bit carrier has an upwardly and outwardly tapering face 2| as clearly shown in Figures 1 and 2 and anchored to the body and projecting inwardly into the slots 6 are the studs 23 arranged to co-act with said tapering faces as hereinafter explained.

When the tool has been lowered to where it is desired to make a cut, it may then be elevated and the upper free ends of the arms II will engage underneath the coupling I 9 above and upon a further upward pull on the operating string, the pin 8 will be sheared and the body will move upwardly relative to the cutter assembly. The

studs 23 will ride against the faces 2I and force the cutter carriers I2 inwardly and the lower ends of the toggle levers I4 will seat against the seats I6 with the pins I8 in the upper ends of the slots I! as shown in Figure 2. This slot I1 is necessary in order to allow the free inward swinging movement to the cutter assembly.

As the body I is pulled upwardly, the operating string and tool will be rotated. The bits I3 will be forced inwardly into cutting relation with the pipe land upon rotation of the tool, the pipe will be severed, as shown in Figure 2. When the pipe is severed, the tool may be withdrawn, the anchor ring assembly 9, I resting on the shoulder and the arms II engaging underneath the coupling 9 so as toremove the severed section with the tool when the tool is withdrawn from the well.

Special attention is called to the construction of the cutter assembly embodying the bit carrier I 2 and the toggle lever I4 50 connected thatupon upward movement of the body relative to the bit carriers, the bits will be forced inwardly in atrue radial-direction andunder theinfiuence of the toggle action between the-toggle levers I4 and the corresponding bit carriers I2.

' The drawing and description are illustrative merely while the broad principle of the invention will be defined by-the appended claims.

What I claimis:

1. A pipe cutter shaped to telescope'with a pipe stuck in a well and comprising a body-provided with a longitudinal side slot, meansassociated with the body and engageable with the stuck pipe, upon upward movement of the body, said means including an anchor, a cutter assembly in the slot and including a carrier whose upper end is'pivoted to the anchor and a toggle lever whose lowerend is pivoted to the body and whose upper end is pivoted to the'ca'rrier, and a radially directed cutting-bit on the cutter assembly. 7

' 2. A pipecutter adapted-t0 cut by rotation and comprising a body shaped to telescope with a pipe stuck in a well, said body having a longitudinal side slot, means carried by'the body and engageable with the stuck pipe, upon upward movement of the body, saidmeans including an anchor, shearable means for attaching the anchor to the body, a cutter assembly in the slot, said assembly including a bit carrier pivoted to the anchor and a toggle lever pivoted to the body and also pivoted to the carrier and a radially directed cutting bit on the carrier adapted to be moved by said assembly into cutting relation with the pipe upon upward movement of the body relative to the pipe.

3. A pipe cutter adapted to cut by rotation and comprising a bodyshaped to telescope with a pipe stuck in a welLsaid body having a longitudinal side slot, means associated with the body and engageable with the stuck pipe, upon upward movement of the body, said means including an anchor, means for temporarily securing the anchor against movement relative to the body, a cutter assembly in the slot and including a bit carrier Whose upper end is pivoted to the anchor and a toggle lever whose lower end is pivoted to the body and whose upper end is pivoted to the carrier, co-acting means for moving the carrier radially upon initial upward movement of the body relative to the anchor and a radially directed bit on the carrier.

4. A pipe cutter adapted to out by rotation and comprising a body shaped to telescope with a pipe stuck in a well, said body having a plurality of longitudinal side slots, means associated with the body and engageable with the stuck pipe upon upward movement of the body, said means including upper and lower anchors rotatable relative to each other and upwardly converging flexible arms carried by the upper anchor, means for temporarily securing the lower anchor against movement relative to the body, a cutter assembly in each slot, each assembly including a bit carrier whose upper end is pivoted to the lower anchor and a toggle lever Whose lower end is pivoted to the body and whose upper end is pivoted to the corresponding carrier and a radially directed cutting bit on'each carrier.

5. A pipe cutter adapted to cut by rotation and comprising a cutter body shaped to telescope with a pipe stuck in a well, said body having a plurality of longitudinal side slots, means associated with the body and engageable with the stuck pipe upon upward movement of the body relative to the pipe, said means including upper and lower anchors rotatable relative to each other and pipe engaging devices carried by the upper anchor, shearable means for temporarily securing the lower anchor against move ment relative to the body, a cutter assembly in each slot, each assembly including a bit carrier whose-upper end is pivoted to the lower anchor, a radially directed cutting bit carried by the free end of each anchor and a toggle lever whose lower end is pivoted to the body and whose upper end is pivoted to the corresponding carrier between the bit and the pivoted end of the carrier.

6. A pipe cutter shaped to telescope with a pipe stuck in a well and comprising a body provided with a longitudinal side slot, means associated with the body and engageable with a stuck pipe, upon longitudinal movement of the body relative to the pipe, said means including an anchor, a cutter assembly in the slot and including a bit carrier and a toggle lever pivotally connected together, the ends of said carrier being pivoted to the anchor and body respectively and a radially directed cutting bit on the carrier.

BERNICE M. SCIVALLY. 

